Check if account has been negative for a period

[Jan Thøgersen]

Hi all,

I'm trying to find a way to check if a users account has been negative for a week or more. I need the information to send out payment reminders.

I store the absolute value of the account in a new record for every transaction. I can't be sure that there has been made any records within the past week. Making a query for the period may result in an empty result.

How can I determine if my users account has been negative for a week?

The table:

CREATE TABLE `user_accounts` (
`id` int(10) UNSIGNED NOT NULL,
`user_id` int(10) UNSIGNED NOT NULL,
`by_id` int(10) UNSIGNED DEFAULT NULL,
`transaction_description` char(128) COLLATE utf8_unicode_ci NOT NULL,
`transaction_amount` decimal(10,2) NOT NULL,
`current_balance` decimal(10,2) NOT NULL,
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;


Thank you in advance!!

/Jan